Semiconductor chips have become progressively more complex, driven in large part by the need for increasing processing power in a smaller chip size for compact or portable electronic devices such as cell phones, smart phones, personal media systems, or ultraportable computers.
Typically, semiconductor chips are interconnected with other circuitry via an integrated circuit package that interfaces with semiconductor chips and attaches to a printed circuit board (PCB). One of the integrated circuit (IC) packages is a ball grid array (BGA) package.
Usually, a BGA package has an array of solder bumps attached to solder bump pads on a bottom external surface of a package substrate. The semiconductor chips or dies are attached to the IC package substrate. The signals of the semiconductor chips or dies are bonded with the package substrate via wires.
One type of the integrated circuit package is a wafer-level BGA package. In a Wafer-level BGA package, solder bumps are mounted directly to I/O pins of the IC chip before the chip is diced from the wafer. Wafer-level BGA package offers smaller footprint with high pin out comparing to other types of IC package.
Typically, I/O pads are adhered to solder bumps with one or more layers of metal, called under bump metallization layers. Under bump metallization (UBM) layers provide connectivity to integrated circuits while also providing greater adhesion for interconnects and protection from the outside. However, creating UBM structures at small scales with the required precision can be a difficult, time-consuming and expensive process.
Thus, a need still remains for a precise and cost-effective way of creating a UBM structure. In view of the shrinking sizes of electronic components, it is increasingly critical that answers be found to these problems. In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is critical that answers be found for these problems. Additionally, the need to reduce costs, improve efficiencies and performance, and meet competitive pressures adds an even greater urgency to the critical necessity for finding answers to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.